Glaucoma

Owls Head — Glaucoma is a disease causing an increase in the internal pressure of one or both eyes. The disease does not interfere with vision until the pressures get so high that it is incompatible with the maintenance of normal eye biology and function. Primary glaucoma is not associated with any other event or problem within the eye. It is usually breed related and often hereditary in nature. Some canine breeds associated with the disease are Cocker Spaniel, Miniature Poodle, Beagle, Basset Hound, Chow Chow, Dalmatian, Shar-Pei, and others. When glaucoma is primary, the opposite, unaffected eye may also develop glaucoma. Veterinary studies indicate an incidence of 50% involvement of the opposite eye within 2 years following the diagnosis of glaucoma in the first eye. Secondary glaucoma is the result of an event or trauma to the eye. Causes of secondary glaucoma include: inflammation, infection, lens luxation, cancer, retinal detachment, and direct trauma. Acute glaucoma is a true medical and ultimately surgical emergency. The diagnosis is made based on the owner's history and the animal's clinical signs. Chronic glaucome implies changes within the eye that cause irreversible loss of vision. The clinical changes most indicative of chronic glaucoma are retinal and optic nerve degeneration and bulging of the eye. In order to diagnose and treat glaucoma, the veterinarian will use a tonometer to measure the pressure within the eye(s). Generally both eyes are evaluated to serve as a base-line and guide to therapeutic management. The treatment of glaucoma is divided into medical and surgical approaches. If the glaucoma is acute, a return of a portion, or all, of the animal's vision is possible. In acute glaucoma, immediate aggressive medical therapy is required to reduce the intraocular (within eye) pressure to within normal range. Failure of medical therapy to lower and maintain correct pressure indicates the need for surgical intervention and the possible referral to a board-certified veterinary ophthalmologist. The appropriate treatment for chronic glaucoma is surgery, the goal of which is to reduce the intraocular pressure, thereby relieving pain and discomfort. Medical therapy of chronic glaucoma is neither effective nor cost-effective over time. The surgery choice is either placement of an intraocular prosthesis or the removal of the diseased eye (enucleation). The placement of an ocular prosthetic maintains a cosmetic appearance of the animal but is not necessary if the goal is only to provide comfort. If you notice any enlargement or bulging of an eye, it is best to have the animal examined by a licensed veterinarian. If you are purchasing a pup whose breed is known to have hereditary glaucoma, it is essential that the parents of the dog have been declared glaucoma-free by a certified ophthalmologist. The certification process must be done annually. If you have any questions concerning glaucoma, please give your vet a call.